Charging unit



FIG. 1 is a front view of a charging unit according to the present invention;

FIG. 2 is a rear view of the charging unit of FIG. 1;

FIG. 3 is a top view of the charging unit of FIG. 1; and,

FIG. 4 is a bottom view of the charging unit of FIG. 1. 

The ornamental design for a charging unit, as shown and described. 